Viscous substances such as silicon glue are often used in construction for sealing crevasses or adhering surfaces to each other. These substances are typically applied through utensils such as a caulk gun, which enable pushing the substance out of the container in which it is stored in order to apply it onto a surface or to fill in crevasses.
Conventional hand-held material dispensing devices rely on the action of a piston to push paste-like materials out of a tube's nozzle. The movement of the piston may be induced by employing mechanical means such as a trigger or a spring; Typically, a rod is used to push forward the moveable cap of standard containers. The rod needs to be as long as the longest commercially available container, and positioned behind the container's cap.
Using a rod makes conventional caulk guns long and heavy. Use of such devices is cumbersome, particularly in tight places that can be reached only with compact instruments.
Several improvements have been made to the operation mechanism of such material dispensing devices. U.S. Pat. No. 5,887,765 titled “Caulk Gun” to Dripless Inc. adds a biasing mechanism to relieve the back pressure inside the caulk tube while maintaining the position of the piston during a given trigger stroke even after the trigger has been released. This mechanism, however, does not contribute to the reduction of size or weight of such a caulk gun.
Similarly, U.S. Pat. No. 4,386,717 titled “Dispenser Having Hose-Like Expandable Member” to Freidrich Koob describes a device for measured discharge of viscous substance which appears to be relatively compact. This device, however, requires that the container incorporates an expandable hose-like member configured to couple with a propellant or expanding medium which forces the substance through an outlet, and is not compatible with standard containers.
One way to reduce the overall length of caulk guns with containers fitted thereto is to cut the containers' walls behind the piston as the piston advances along the interior of the container. The cutting may be accomplished by urging a blade against the container walls during the employment of the caulk gun.
For example, JP63185475 to WAKAI SANGYO is directed to a caulk gun with a cutting blade, in the rear of a pressing plate, both of which advance from the back to the front along a cartridge. The gun has a mechanism for holding a cartridge vessel, and a feeding mechanism is provided for moving the pressing plate, the vessel cutting blade advancing in cooperation with the pressing plate. Contents in the vessel are discharged by the advancement of the pressing plate.
U.S. Pat. No. 6,640,998 to ALBION ENGINEERING COMPANY describes a caulking gun having a hand-held trigger operating clamp with a blade mounted on the clamp whereby the clamp and a bar cooperate to cause a cartridge containing caulk to move axially against a fixed plunger mounted on the clamp and the blade servers the cartridge containing caulk to permit the plunger to be advanced the length of the cartridge containing caulk.
U.S. Pat. No. 3,606,085 to Ian Butler Spilman depicts a dispensing gun with a handle mounting a support at its upper end, a thrust member mounted on the support and rising thereabove for engagement and cooperation with a piston member for expressing the contents of a substance container, guide means in the support, a carriage moveable through the guide means and normally arranged to extend forwardly of the handle, a container holder mounted on the forward part of the carriage and arranged so that an outlet nozzle end part of the container may be held and supported between the forward container holder and the thrust member, a moveable trigger associated with the handle, a carriage moving means associated with the carriage and operable by the trigger to move the carriage in the guide means a desired distance, the construction providing that squeezing the trigger into or towards the handle causes the carriage moving means to move the carriage with the container a prescribed distance relative to the thrust member associated with the piston member for the container in delivering and dispensing a desired amount of substance from the container.
US20080006654 to John Lampe and Douglas Oudekerk describes a device for dispensing flowable materials such as caulk, including for example a cartridge and a dispenser with: a drive mechanism for advancing a pusher forward, the drive mechanism having at least one fulcrum positioned forward of the pusher during operation of the dispenser; a cutter that cuts a slit in a wall of the cartridge for purposes of dispensing a flowable material, and a winch for driving the dispensing of a flowable material from the cartridge.
WO2007144434 to Seamus and Tracey Devlin is directed to a sealant gun or like device that includes a hollow cylindrical barrel containing sealant or other viscous material, a plunger located in the barrel, and a drive mechanism for effecting relative axial movement between the plunger and the barrel to eject the material from a nozzle at the front of the barrel. The drive mechanism includes means for engaging the barrel progressively along its length to draw the barrel rearwardly relative to the drive mechanism and plunger. In particular, engaging means described therein are for progressively separating at least one longitudinal strip of the barrel to provide a slot through which a part of the drive mechanism can project and the drive mechanism includes a cutting means for separating the longitudinal strip.
The drive mechanism is described to be for example include a support, a grip ring loosely surrounding the barrel at the front of the support, means resiliently biasing the grip ring and support apart in the axial direction of the barrel, and an actuator for repeatedly tilting the grip ring to grip the barrel, moving the grip ring rearwardly against the resilient bias while the barrel is gripped, and releasing the grip ring to allow it to be moved forwardly along the barrel by the resilient bias, thereby to draw the barrel incrementally in a rearward direction.
Means for engaging with the barrel is described to preferably include an endcap for locating at the front of the barrel, and a cable connecting the endcap to the drive mechanism.
Cutting means is described to preferably include at least one cutting wheel, the cutting wheel acting on the surface of the barrel to cut the surface of the barrel to be received, and preferably, the cutting means include at least one internal cutting wheel and at least one external cutting wheel, the at least one internal cutting wheel mounted within the housing acting on the internal surface of the barrel, the at least one external cutting wheel mounted within the housing acting on the external surface of the barrel.
Although the device described in WO2007144434 may be considerably shorter than the length of the uncut barrel, the force employed to engage and pull the strip, together with additional forces employed to perform the additional operations occurring during the strip pulling (such as extrusion of viscous material), require the device to be unwieldy massive.
None of the references discussed above require nor recognize the advantage of having teeth on a cutting-pushing element to dispensing devices.
The need remains, therefore, for compact, simple, lightweight, hand-held viscous material dispensing devices that can be used in small confined locations and may be coupled with various sizes of viscous material containers. Embodiments described hereinbelow address this need.